Many different industries require power supplies for supplying constant power based on a three-phase power source.
Cyclo-converters have been developed for use in efficient power supplies in order to provide a number of improvements over conventional rectifier power supplies and two stage power supplies.
A cyclo-converter provides an efficient single stage power converter. A benefit of adopting single stage power conversion is based on the fact that a single stage converter will have an efficiency similar to the efficiency of either of the individual stages of a conventional two-stage rectifier (e.g. 96%). In other words the losses from a single-stage converter are only half of that of a two-stage converter. This greater efficiency (lower losses) leads to a corresponding decrease in the size of components within the rectifier and hence a smaller product that costs less to produce. Other benefits are obtained by virtue that the exhaust air heat from the converter will be lower for a given system power (easing power system design) and in the fact that a single-stage converter can be realised with considerably fewer components than a conventional two-stage rectifier design.
The present applicants have developed a unique three-phase resonant cyclo-converter configuration as described in PCT publication WO2008/018802, which is hereby incorporated by reference.
This present application relates to an improved method (and associated control system) for controlling the power transfer and power factor of a three-phase resonant cyclo-converter, such as the type described in WO2008/018802. It will be appreciated that although power converters such as those described in WO2008/018802 are particularly useful in the telecommunication industry that they may also equally be applicable in other industries.
Embodiments of the present invention provide an improved mechanism for controlling the power transfer and the power factor of a three phase resonant cyclo-converter.
An object of the present invention is to provide improved control over existing three-phase resonant cyclo-converters.
A further object of the present invention is to provide improved control of the power transfer function of a three-phase resonant cyclo-converter.
A further object of the present invention is to provide improved control of the power factor of a three-phase resonant cyclo-converter.
Each object is to be read disjunctively with the object of at least providing the public with a useful choice.
The present invention aims to overcome, or at least alleviate, some or all of the afore-mentioned problems.